This invention relates to an ink jet recording apparatus provided with a cleaning mechanism for cleaning the ink discharging surface of an ink jet recording head for discharging ink to a recording material to thereby effect recording, and particularly to an ink jet recording apparatus provided with a cleaning mechanism of a roller type which makes improved cleaning possible.
A recording apparatus having the function of a printer, a copying apparatus, a facsimile apparatus or the like, or a recording apparatus used as the output instrument of a compound type electronic apparatus including a computer, a word processor or the like or of a work station is designed to record images (including characters, symbols, etc.) on a recording material such as recording paper or a plastic sheet on the basis of recording information. Such recording apparatus can be grouped into an ink jet type, a wire dot type, a thermal type, a laser beam type, etc. depending on the recording system thereof.
Among these, a recording apparatus of the ink jet type (ink jet recording apparatus) discharges ink from recording means (recording head) to a recording material to thereby effect recording, and has the advantages that it is easy to make the recording means compact, highly accurate images can be recorded at a high speed, recording can be done without requiring any special treatment of plain paper, the running cost is low and due to its being a non-impact system, noise is little and moreover, it is easy to use many kinds of inks (e.g., color inks) to second color images.
Also, there are various requirements for the quality of the recording material and in recent years, development for these requirements has been advanced, and recording apparatuses using, besides paper (including paper sheets and worked paper) which is an ordinary recording material and resin sheets (OHP or the like), cloth, leather, unwoven fabrics and metals or the like as recording materials have come to be used.
In the above-described ink jet recording apparatus, ink is discharged from minute discharge ports formed in the discharging surface of a recording head to recording paper, and the recording paper and the recording head are moved relative to each other to thereby effect recording. Therefore, there may result a situation in which ink droplets, dust or paper powder adheres to the discharging surface and the adhering materials are solidified, and this has affected the discharged state of the ink and in some cases, has resulted in non-discharge.
With a view to improve such a situation, generally a cleaning mechanism is provided in the apparatus and a cleaning operation is executed for the discharging surface of the recording head periodically or at predetermined timing so as to remove the foreign substances such as ink droplets, dust, paper powder and solidified materials, and this is an important technical element in ink jet recording.
There have been proposed various examples of the construction for cleaning adopted in the ink jet recording apparatus. They include, for example, a construction in which a plate-like elastic member is brought into frictional contact with the discharging surface (Japanese Laid-Open Patent Application No. 6-340082 and Japanese Laid-Open Patent Application No. 7-9674), a construction in which an absorbent member is brought into frictional contact with the discharging surface (Japanese Laid-Open Patent Application No. 7-52396), and a construction in which a rotatable member is rotated and the discharging surface is brought into frictional contact therewith (Japanese Laid-Open Patent Application No. 57-63267, Japanese Laid-Open Patent Application No. 57-193369, Japanese Laid-Open Patent Application No. 62-288047, Japanese Laid-Open Patent Application No. 6-255117 and Japanese Laid-Open Patent Application No. 7-96604).
FIGS. 11 through 14A, 14B and 14C of the accompanying drawings schematically shows some examples of the cleaning mechanism.
FIG. 11 shows an example of the construction which uses a plate-like elastic member (a wiping blade) to effect cleaning and in which on one end portion off the recording area of a recording apparatus 101, a wiping blade 104 is disposed as one of recovery mechanisms 102 adjacent to a capping mechanism 103. The wiping blade 104 utilizes the movement of a recording head 106 carried on a carriage 105 to the recovery mechanisms 102 to frictionally contact with the discharging surface and effect cleaning.
FIG. 12 shows an example of the cleaning mechanism in which an absorbent member 110 is disposed, and with a view to well remove a solidified material which cannot be removed by a wiping blade 104, the absorbent member 110 is disposed at a location adjacent to the wiping blade 104 and utilizes the movement of a recording head to the recovery mechanisms 102 to frictionally contact with the discharging surface and effect cleaning.
FIGS. 13A and 13B show examples of the cleaning construction utilizing a rotatable member 111, and without utilizing the movement of a carriage, the rotatable member 111 itself rotates while being in contact with the discharging surface 106a of a recording head 106 to thereby execute cleaning. The examples shown in FIGS. 13A and 13B are a construction in which the rotatable member is disposed in a cap mechanism, and after the recording head has been capped by a capping member, as shown in FIG. 13A, the rotatable member 111 is moved so as to contact with the discharging surface 106a, and in response to the rotatable force of another rotatable member 112 connected to a drive source in the direction of arrow a, the rotatable member 111 is rotated in the direction of arrow b and cleans the discharging surface 106a. At a point of time whereat the cleaning has been completed, as shown in FIG. 13B, the rotatable member 111 is moved to its initial position separate in the direction of arrow e from the discharging surface 106a. 
FIGS. 14A to 14C show another examples of the cleaning construction utilizing a rotatable member. In these examples, the rotatable member 111 is moved on the discharging surface 106a while being rotated to thereby make it possible to clean the entire discharging surface. In the construction shown in FIGS. 14A to 14C, the rotatable member 111 executes its rotating operation by having a rotating operation from another rotatable member 112 transmitted thereto, and by the movement of said another rotatable member 112 with an arm 113 extending from the center of rotation thereof to the rotatable member as the radius, the rotatable member is moved from one side to the other side of the discharging surface 106a to thereby clean the entire discharging surface. At this time, the direction of rotation of the rotatable member is the same direction (arrow f in FIG. 14A and arrow p in FIG. 14B) as the direction of movement (arrow m in FIG. 14B) of the rotatable member, whereby firm cleaning is made possible.
For example, in the construction of a cleaning member using an absorbent member, however, an adhering substance comes to remain with an increase in the frequency of frictional contact and in some cases, sufficient cleaning performance cannot be expected. Also, the surface of the absorbent member becomes roughened by an increase in the frequency of the frictional contact with the discharging surface, and the cleaning performance may be gradually deteriorated.
Also, in the construction wherein the movement of the rotatable member and the rotation of the rotatable member are in the same direction and cleaning is effected, the load to the discharging surface is great, thus helping the deterioration of the characteristic of the rotatable member or scraping off the water repellent finish provided on the discharging surface, or these become complex and injure the discharging surface, and this has led to the possibility that ink discharging performance cannot be recovered in spite of the recovering process being carried out.
The present invention intends to improve the situation as noted above and an object thereof is to provide an ink jet recording apparatus which is provided with cleaning means capable of maintaining stable cleaning performance for a long period when cleaning the discharging surface of a recording head and which can achieve stable ink discharge for a long period.
It is also an object of the present invention to provide a construction which reduces a load to a cleaning member in cleaning and yet can sufficiently obtain the cleaning effect, and to provide an ink jet recording apparatus which secures sufficient cleaning performance and also maintains ink discharging performance.
It is also an object of the present invention to provide an ink jet recording apparatus for discharging ink from recording means to a recording material to thereby effect recording, characterized by a contacting member for cleaning the discharging surface of the recording means, the contacting member being rotatable until immediately before it contacts with the discharging surface, and the rotation being fixed when the contacting member contacts with the discharging surface.
It is also an object of the present invention to provide an ink jet recording apparatus for discharging ink from recording means to a recording material to thereby effect recording, characterized by a contacting member for cleaning the discharging surface of the recording means, the contacting member being moved relative to the discharging surface while being in contact with the discharging surface during paper feeding reverse rotation, the contacting member being rotated and in contact with a re-transfer member during further paper feeding reverse rotation, the contacting member being returned to its initial position during paper feeding forward rotation.
It is a further object of the present invention to provide an ink jet recording apparatus for discharging ink from recording means to a recording material to thereby effect recording, characterized by a contacting member for cleaning the discharging surface of the recording means, and a cap member for protecting the discharging surface, the contacting member and the cap member being disposed on opposite sides with a recording area therebetween.